This invention relates to pneumatic pressure controllers who, when interacting with separate control valves, are able to control the pressure of fluid in a given piping system.
The objective of my present invention is to provide a very simple and inexpensive pressure controller especially for use in bioprocessing applications where the wetted process side has to not only be aseptic but also be suitable to be periodically cleaned with harsh chemicals but also sterilized with live steam. In addition, the process area has to be self-draining and cannot have any crevices that could support micro-organisms.
An additional requirement is the provision of a double-diaphram on the process side which protects the external environment in case the primary diaphragm sensing the process ruptures.
Finally, my invention shall constitute a very rugged and simple design to withstand external cleaning and vibrations. All these requirements will be met and become clear from the following detailed description.